import {ApiError} from 'app/common/ApiError'; import {BrowserSettings} from 'app/common/BrowserSettings'; import {ErrorWithCode} from 'app/common/ErrorWithCode'; import {UserProfile} from 'app/common/LoginSessionAPI'; import {getLoginState, LoginState} from 'app/common/LoginState'; import {ANONYMOUS_USER_EMAIL} from 'app/common/UserAPI'; import {User} from 'app/gen-server/entity/User'; import {HomeDBManager} from 'app/gen-server/lib/HomeDBManager'; import {ActiveDoc} from 'app/server/lib/ActiveDoc'; import {Authorizer} from 'app/server/lib/Authorizer'; import {DocSession} from 'app/server/lib/DocSession'; import * as log from 'app/server/lib/log'; import {ILoginSession} from 'app/server/lib/ILoginSession'; import {shortDesc} from 'app/server/lib/shortDesc'; import * as crypto from 'crypto'; import * as moment from 'moment'; /// How many messages to accumulate for a disconnected client before booting it. const clientMaxMissedMessages = 100; export type ClientMethod = (client: Client, ...args: any[]) => Promise; /** * Generates and returns a random string to use as a clientId. This is better * than numbering clients with consecutive integers; otherwise a reconnecting * client presenting the previous clientId to a restarted (new) server may * accidentally associate itself with a wrong session that happens to share the * same clientId. In other words, we need clientIds to be unique across server * restarts. * @returns {String} - random string to use as a new clientId. */ function generateClientId(): string { // Non-blocking version of randomBytes may fail if insufficient entropy is available without // blocking. If we encounter that, we could either block, or maybe use less random values. return crypto.randomBytes(8).toString('hex'); } /** * These are the types of messages that are allowed to be sent to the client even if the client is * not authorized to use this instance (e.g. not a member of the team for this subdomain). */ const MESSAGE_TYPES_NO_AUTH = new Set([ 'clientConnect', 'profileFetch', 'userSettings', 'clientLogout', ]); // tslint:disable-next-line:no-unused-expression Silence "unused variable" warning. void(MESSAGE_TYPES_NO_AUTH); /** * Class that encapsulates the information for a client. A Client may survive * across multiple websocket reconnects. * TODO: this could provide a cleaner interface. * * @param comm: parent Comm object * @param websocket: websocket connection, promisified to have a sendAsync method * @param methods: a mapping from method names to server methods (must return promises) */ export class Client { public readonly clientId: string; public session: ILoginSession|null = null; public browserSettings: BrowserSettings = {}; // Maps docFDs to DocSession objects. private _docFDs: Array = []; private _missedMessages: any = []; private _destroyTimer: NodeJS.Timer|null = null; private _destroyed: boolean = false; private _websocket: any; private _loginState: LoginState|null = null; private _org: string|null = null; private _profile: UserProfile|null = null; private _userId: number|null = null; private _firstLoginAt: Date|null = null; private _isAnonymous: boolean = false; // Identifier for the current GristWSConnection object connected to this client. private _counter: string|null = null; constructor( private _comm: any, private _methods: any, private _host: string ) { this.clientId = generateClientId(); } public toString() { return `Client ${this.clientId} #${this._counter}`; } // Returns the LoginState object that's encoded and passed via login pages to login-connect. public getLoginState(): LoginState|null { return this._loginState; } public setCounter(counter: string) { this._counter = counter; } public get host(): string { return this._host; } public setConnection(websocket: any, reqHost: string, browserSettings: BrowserSettings) { this._websocket = websocket; // Set this._loginState, used by CognitoClient to construct login/logout URLs. this._loginState = getLoginState(reqHost); this.browserSettings = browserSettings; } /** * Returns DocSession for the given docFD, or throws an exception if this doc is not open. */ public getDocSession(fd: number): DocSession { const docSession = this._docFDs[fd]; if (!docSession) { throw new Error(`Invalid docFD ${fd}`); } return docSession; } // Adds a new DocSession to this Client, and returns the new FD for it. public addDocSession(activeDoc: ActiveDoc, authorizer: Authorizer): DocSession { const fd = this._getNextDocFD(); const docSession = new DocSession(activeDoc, this, fd, authorizer); this._docFDs[fd] = docSession; return docSession; } // Removes a DocSession from this Client, called when a doc is closed. public removeDocSession(fd: number): void { this._docFDs[fd] = null; } // Check that client still has access to all documents. Used to determine whether // a Comm client can be safely reused after a reconnect. Without this check, the client // would be reused even if access to a document has been lost (although an error would be // issued later, on first use of the document). public async isAuthorized(): Promise { for (const docFD of this._docFDs) { try { if (docFD !== null) { await docFD.authorizer.assertAccess('viewers'); } } catch (e) { return false; } } return true; } /** * Closes all docs. */ public closeAllDocs() { let count = 0; for (let fd = 0; fd < this._docFDs.length; fd++) { const docSession = this._docFDs[fd]; if (docSession && docSession.activeDoc) { // Note that this indirectly calls to removeDocSession(docSession.fd) docSession.activeDoc.closeDoc(docSession) .catch((e) => { log.warn("%s: error closing docFD %d", this, fd); }); count++; } this._docFDs[fd] = null; } log.debug("%s: closeAllDocs() closed %d doc(s)", this, count); } public interruptConnection() { if (this._websocket) { this._websocket.removeAllListeners(); this._websocket.terminate(); // close() is inadequate when ws routed via loadbalancer this._websocket = null; } } /** * Sends a message to the client, queuing it up on failure or if the client is disconnected. */ public async sendMessage(messageObj: any): Promise { if (this._destroyed) { return; } const message: string = JSON.stringify(messageObj); // Log something useful about the message being sent. if (messageObj.type) { log.info("%s: sending %s: %d bytes", this, messageObj.type, message.length); } else if (messageObj.error) { log.warn("%s: responding to #%d ERROR %s", this, messageObj.reqId, messageObj.error); } else { log.info("%s: responding to #%d OK: %d bytes", this, messageObj.reqId, message.length); } if (this._websocket) { // If we have a websocket, send the message. try { await this._websocket.sendAsync(message); } catch (err) { // Sending failed. Presumably we should be getting onClose around now too. // NOTE: if this handler is run after onClose, we could have messages end up out of order. // Let's check to make sure. If this can happen, we need to refactor for correct ordering. if (!this._websocket) { log.error("%s sendMessage: UNEXPECTED ORDER OF CALLBACKS", this); } log.warn("%s sendMessage: queuing after send error: %s", this, err.toString()); this._missedMessages.push(message); } } else if (this._missedMessages.length < clientMaxMissedMessages) { // Queue up the message. this._missedMessages.push(message); } else { // Too many messages queued. Boot the client now, to make it reset when/if it reconnects. log.error("%s sendMessage: too many messages queued; booting client", this); if (this._destroyTimer) { clearTimeout(this._destroyTimer); this._destroyTimer = null; } this._comm._destroyClient(this); } } // Assigns the client to the given login session and the session to the client. public setSession(session: ILoginSession): void { this.unsetSession(); this.session = session; session.clients.add(this); } // Unsets the current login session and removes the client from it. public unsetSession(): void { if (this.session) { this.session.clients.delete(this); } this.session = null; } public destroy() { this.unsetSession(); this._destroyed = true; } /** * Processes a request from a client. All requests from a client get a response, at least to * indicate success or failure. */ public async onMessage(message: string): Promise { const clientId = this.clientId; const request = JSON.parse(message); if (request.beat) { // this is a heart beat, to keep the websocket alive. No need to reply. log.rawInfo('heartbeat', {clientId, counter: this._counter, url: request.url}); return; } else { log.info("%s: onMessage", this, shortDesc(message)); } const response: any = {reqId: request.reqId}; const method = this._methods[request.method]; if (!method) { response.error = `Unknown method ${request.method}`; } else { try { response.data = await method(this, ...request.args); } catch (error) { const err: ErrorWithCode = error; // Print the error stack, except for SandboxErrors, for which the JS stack isn't that useful. // Also not helpful is the stack of AUTH_NO_VIEW|EDIT errors produced by the Authorizer. const code: unknown = err.code; const skipStack = ( !err.stack || err.stack.match(/^SandboxError:/) || (typeof code === 'string' && code.startsWith('AUTH_NO')) ); log.warn("%s: Error %s %s", this, skipStack ? err : err.stack, code || ''); response.error = err.message; if (err.code) { response.errorCode = err.code; } if (typeof code === 'string' && code === 'AUTH_NO_EDIT' && err.accessMode === 'fork') { response.shouldFork = true; } } } await this.sendMessage(response); } public setOrg(org: string): void { this._org = org; } public getOrg(): string { return this._org!; } public setProfile(profile: UserProfile|null): void { this._profile = profile; // Unset userId, so that we look it up again on demand. (Not that userId could change in // practice via a change to profile, but let's not make any assumptions here.) this._userId = null; this._firstLoginAt = null; this._isAnonymous = !profile; } public getProfile(): UserProfile|null { if (this._isAnonymous) { return { name: 'Anonymous', email: ANONYMOUS_USER_EMAIL, anonymous: true, }; } return this._profile; } public getCachedUserId(): number|null { return this._userId; } public isAnonymous(): boolean { return this._isAnonymous; } // Returns the userId for profile.email, or null when profile is not set; with caching. public async getUserId(dbManager: HomeDBManager): Promise { if (!this._userId) { if (this._profile) { const user = await this._fetchUser(dbManager); this._userId = (user && user.id) || null; this._isAnonymous = this._userId && dbManager.getAnonymousUserId() === this._userId || false; this._firstLoginAt = (user && user.firstLoginAt) || null; } else { this._userId = dbManager.getAnonymousUserId(); this._isAnonymous = true; this._firstLoginAt = null; } } return this._userId; } // Returns the userId for profile.email, or throws 403 error when profile is not set. public async requireUserId(dbManager: HomeDBManager): Promise { const userId = await this.getUserId(dbManager); if (userId) { return userId; } throw new ApiError(this._profile ? `user not known: ${this._profile.email}` : 'user not set', 403); } public getLogMeta() { const meta: {[key: string]: any} = {}; if (this._profile) { meta.email = this._profile.email; } // We assume the _userId has already been cached, which will be true always (for all practical // purposes) because it's set when the Authorizer checks this client. if (this._userId) { meta.userId = this._userId; } // Likewise for _firstLoginAt, which we learn along with _userId. if (this._firstLoginAt) { meta.age = Math.floor(moment.duration(moment().diff(this._firstLoginAt)).asDays()); } if (this._org) { meta.org = this._org; } meta.clientId = this.clientId; // identifies a client connection, essentially a websocket meta.counter = this._counter; // identifies a GristWSConnection in the connected browser tab return meta; } // Fetch the user database record from profile.email, or null when profile is not set. private async _fetchUser(dbManager: HomeDBManager): Promise { return this._profile && this._profile.email ? await dbManager.getUserByLogin(this._profile.email) : undefined; } // Returns the next unused docFD number. private _getNextDocFD(): number { let fd = 0; while (this._docFDs[fd]) { fd++; } return fd; } }